1. Field of the Invention
The present invention relates to gear-driven transmissions and, more particularly, to an improved transmission having a constantly variable automatic transmission.
2. Description of the Background
Most conventional transmissions are step transmissions that require a shifting of gears to change the mechanical advantage and speed between a input shaft and a output shaft. A typical step transmission in an automobile works by mechanically engaging a gear on the output shaft with gears of various sizes on the input shaft. As larger gears on the input shaft engage the gear on the output shaft the torque and the speed on the output shaft changes. Under these conditions the power between the output shaft and the input shaft remains constant.
Step transmission suffer from the following disadvantages:
(1) A shift in mechanical advantage to change speed results in wasted power.
(2) Driving motors such as A/C motors cannot remain at an optimum power output when the output speed changes. This problem is especially acute with A/C motors because changes in speed cause overheating.
(3) Step transmissions are mechanically complex and difficult to construct. They are heavy and require auxiliary controls. The manufacturing cost is high.
Continuously variable transmissions are a well-known alternative to the step-transmission.
For instance, U.S. Pat. No. 4,854,190 shows a continuously variable transmission with a floating gear assembly that provides a wide range of output speeds and torque. The reference points out that the floating gear assembly rotates in opposite direction to the input shaft. The reference does not show an output power.
It would be greatly advantageous to provide a more economical gear transmission with a constantly variable mechanical advantage. This would allow A/C motors to run at an optimum speed while their connected (driven) appliances could vary in speed.